JP 2017-35935A discloses a frame-shaped metal reinforcement disposed on an inner side of a metal door outer panel. The frame-shaped reinforcement is attached along the periphery of the door outer panel. At a front portion of a side door, front end portions of a first bracket and a second bracket are attached to the frame-shaped reinforcement, and rear end portions of the first and second brackets are attached to a front end portion of a reinforcing element (impact beam) to support the reinforcing element.